What Is a Primary Source?
A primary source is original, first-hand evidence about a topic. It comes directly from the time, person or event being studied, without later interpretation. Researchers use primary sources as the raw material of their analysis, and then use secondary sources to see how others have interpreted the same evidence.
Examples by discipline
| Field | Primary sources |
|---|---|
| History | Letters, diaries, speeches, treaties, photographs, newspapers of the time, oral histories |
| Literature | The novel, poem or play being analyzed, manuscripts, author interviews |
| Science | Lab notebooks, original experimental data, a research article reporting new results |
| Social sciences | Survey responses, interview transcripts, field notes, census data |
| Law | Statutes, court decisions, contracts |
| Art | Paintings, sculptures, artists' statements |
| Politics | Government documents, speeches, legislation, polls |
Whether a source is primary depends on your question. A newspaper article from 1950 is primary evidence for how the media described an event, and a secondary source if you use it only to find out what happened.
Primary versus secondary
Secondary sources analyze, interpret or summarize primary sources, such as a textbook, a review article or a documentary. Tertiary sources, such as encyclopedias, collect and condense information. Most research uses all three.
Analyzing a primary source
Ask a standard set of questions:
- Who created it, and what was their position?
- When and where was it created?
- Why was it made, and for whom?
- What does it say, and what does it leave out?
- How reliable is it, and how does it compare with other evidence?
- What does it reveal about your research question?
Consider bias, purpose and context. A government report, for example, may emphasize successes.
Where to find them
- Libraries and archives, including digital collections.
- Government websites and databases.
- University special collections.
- Data repositories for scientific and social science data.
- Your own research, such as interviews and experiments.
Citing
Cite primary sources according to your style guide, giving details such as author, date, location in an archive or collection and the access path. Quote carefully, and explain the context.
Why it matters
Using primary sources shows that you engage with evidence and not only with others' opinions, which is a mark of strong research.
Related terms
See secondary source, scholarly journal, gray literature, citation style and bibliography.
Frequently asked questions
What is an example of a primary source?
A diary, a speech, a photograph from the time, a government report, an interview you conducted, raw data from an experiment or a work of literature being analyzed.
Can the same item be primary or secondary?
Yes, depending on your question. A newspaper article is a primary source for studying how an event was reported, and a secondary source if used to learn facts about the event.
Are primary sources always more reliable?
Not always. They can be biased, incomplete or inaccurate. They provide direct evidence, but need to be interpreted in context.